| There are a few network parameters that can be tuned to better match | |
| the kernel to your system hardware and intended usage. The defaults | |
| are usually a good choice for 99% of the people 99% of the time, but | |
| you should be aware they do exist and can be changed. | |
| The current list of parameters can be found in the files: | |
| linux/net/TUNABLE | |
| Documentation/networking/ip-sysctl.txt | |
| Some of these are accessible via the sysctl interface, and many more are | |
| scheduled to be added in this way. For example, some parameters related | |
| to Address Resolution Protocol (ARP) are very easily viewed and altered. | |
| # cat /proc/sys/net/ipv4/arp_timeout | |
| 6000 | |
| # echo 7000 > /proc/sys/net/ipv4/arp_timeout | |
| # cat /proc/sys/net/ipv4/arp_timeout | |
| 7000 | |
| Others are already accessible via the related user space programs. | |
| For example, MAX_WINDOW has a default of 32 k which is a good choice for | |
| modern hardware, but if you have a slow (8 bit) Ethernet card and/or a slow | |
| machine, then this will be far too big for the card to keep up with fast | |
| machines transmitting on the same net, resulting in overruns and receive errors. | |
| A value of about 4 k would be more appropriate, which can be set via: | |
| # route add -net 192.168.3.0 window 4096 | |
| The remainder of these can only be presently changed by altering a #define | |
| in the related header file. This means an edit and recompile cycle. | |
| Paul Gortmaker 06/96 |